function Text () {
  this.x = 0
  this.y = 0
  this.color = '#ffff00'
  this.lineColor = "#000000"
  this.rotation = 0
  this.fontSize = 22
}

Text.prototype.draw = function (context, txt) {
  context.imageSmoothingQuality = 'high'
  context.save()
  // context.translate(this.x, this.y)
  // context.rotate(this.rotation)
  context.textAlign = 'center'
  context.font =  this.fontSize + 'px Microsoft YaHei'
  context.strokeStyle = this.lineColor
  context.fillText(txt, this.x, this.y + this.fontSize/2)
  context.restore()
}